bates



A. H. BATES.

DIE STOCK.

APPLICATION FILED MAR. 8. 1917- 1,305,336. Patented June 3,1919.

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A. H. BATES.

DIE STOCK. APPLICATION man MAR. 8. 1911. I 1,305,336. Patented June 3, 1919.

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"UNITED STATES PATENT ()FFTGE.

ALBERT H. BATES, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THE BORDEN COMPANY, OF WARREN, OHIO, ACORPORATION OF OHIO.

DIE-STOCK.

Application filed March 8, 1917.

'1 b all whom it may concern:

- Be it known that I, ALBERT H. BATES, a citizen of the United States, residing at Cleveland Heights, in the county of Guyahoga and State of Ohio, have invented a certain new and useful Improvement in Die- Sto'cks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to die stocks of the receding chaser type, adapted to cut a tapered thread on a pipe. The primary object of the invention is to provide a device of this character which shall be very simple and cheaply constructed and automatically control the recedence of the chaser as the cutting of the thread progresses. Another object is to enable the cutting of a running thread without recedence of the chasers for any desired distance on a pipe.

My invention is illustrated in the drawings hereof and is herein-after more fully described and its essential characteristics are summarized in the claims. 7

In the drawings Figure 1 is a front elevation ofthe die stock; Fig. 2 is an axial section thereof; Fig. 3 is a perspective view of the stop member and chaser-controlling wedges carried thereby; Figs. 4 and 5 are details, being cross sections of a portion of the chaser-carrying frame, Fig. 4 being in a plane parallel with Fig. 1, Fig. 5 in a plane at right angles to Fig. 4, each of these sections being indicated by the correspond ingly numbered line on the other section. Fig. 6 is a rear elevation on a reduced scale of the chaser-carrying frame.

As 'shown in the drawings, 1 indicates a chaser-carrying frame which may conveniently be a single casting comprising a front plate 2, a sleeve 3, extending from the rear face of the plate and radial housings 4 on the rear side of the plate and the outer side of the sleeve. Radial openings in these housings provide guideways for carrying the chasers. .In addition to the sleeve 3, the plate 2 may be stiffened by an outer circumferential web 5. The frame is preferably provided with integral sockets 8 for the usual handles 9.

v-10 indicates a bushing adapted to occupy the sleeve 3 and engage the surface of a pipe A to be threaded. The interior diameter of the bushing varies with the size of the pipe, as; asset The bushing. is held;

Specification of Letters Patent.

Patented June 3, 1919.

Serial No. 153,388. I

rigidly carries rearwardly extending wedgeshaped arms 31 which project through openings 6 in the front plate, and 7 in the rear wall of the housings. The wedges have their outer edges parallel with the axis. of the die stock and their inner edges tapered according to the taper of the thread to be cut. These inner edges engage the shoulders 22 on the chasers, which are correspondingly inclined.

It will be seen that the wedges form abutments limiting the outward movement of the chasers, and that if the chasers travel relatively to the wedges toward the small ends thereof, they may correspondingly recede to cut a tapered thread. To cause such travel automatically I provide a stop plate 40, rotatably carried by the member 3O and adapted to abut the end of the pipe A. This stop plate is shown as seating in a circular opening 32 in the member 30 and as having an annular flange 4:1 on the inner.

side of the member. As the threading starts, the rotatable plate 40 engages the end of the pipe and prevents the wedges from traveling, and thus as the chaser-carrying frame ,travels along the pipe during the threading, thev receding surfaces of the wedges allow the chasers to recede to cut the tapered thread desired. v

It will be seen that the plate 30is in reality a ring having a circular opening larger than the pipe to be threaded. Accordingly the removal of the plate 40 enables the ring 30 to pass over the pipe being threaded. This provides for cutting running threads on the pipe, the tapered operation being simply stopped at any desired point and the die stock backed off sufliciently to remove the plate 40, and then the threading continued with the chasers in the position they ,thenoceupyh The inclineof as wedges corresponding with the taper of the thread is small enough so that the thrust of the chasers has no effect in displacing the position of the wedges in such operation.

To prevent inadvertent separation of the parts, I prefer to provide nuts 33 on the ends of the wedges 31, the inner end of the wedge being simply reduced to a. cylindrical extension and threaded to carry a nut. To prevent the plate being inadvertently separated from the plate 30, I provide screws 42, mounted in the plate 40 and normally overhanging the plate 30. The screws, however, have their heads removed on one side so that by turning them half way around the plate 40 may be freed from the plate 30. To enable the plate 40 to be removed with out removing the wedges from the rotary frame, it is flattened at two opposite sides, as indicated at 4st, thus making it smaller at such dimension than the distance between any two of the wedges. Accordingly, the plate can be conveniently removed radially between the wedges whenever it is desired to use the die stock without the front stop. This enables the cutting of a running thread on the pipe for any distance desired.

The chasers are inserted in their housing from the inside, and are held against inadvertcnt displacement by any suitable means, as, for example, the plungers 50, pressed against them by leaf springs 51 secured to the front side of the plate 2.

It will be seen that m die stock is of very simple construction. he rotary frame, if desired, may be made of one single casting, and the front plate and wedges may, if desired, be made of a single casting. The rotary stop plate is also a single casting, the chasers are simple in construction, the bushing is of the usual type, and the remaining parts are ordinary screws, nuts, etc.

Having thus described my invention, what I claim is:

1. The combination of a rotary frame hav- 111g radial housings, each with two side walls,

a front wall and a rear wall, chasers having cutters for tapered threads at their inner ends and having cut-away portions to provide transverse shoulders, said chasers occupying the radial housings, wedges extending through openings in the front and rear walls of the housing and lying along the inner face of one of the side walls of the housing and having their inner edge inclined according to the taper of the thread and engaging said shoulders, a transverse plate to which the tapered ends of the wedges are secured, and means carried by said plate for abutting the end of the pipe to be threaded.

2. The combination of a rotary frame, chasers movably carried thereby and having cutters for tapered threads at their inner ends, wedges engaging the chasers and having inner edges inclined according to the taper of the thread to be cut, a ring to which the outer ends of the wedges are secured, and arotary plate removably seated within said ring and against its inner face and adapted to abut the end of the pipe, said plate being incompletely circular and narrow enough to be removed outwardly between adjacent wedges.

3. In a die stock, the combination of a chaser-carrying frame, chasers carried thereby, a movable front ring, means movable by the ring for controlling the recession of the chasers, and an abutment member rotatably secured to said ring by means which enable the freeing of the member on the inner side of the ring, said member having its periphery partially circular but of reduced width at a portion thereofto enable the member to be withdrawn radially between the recession controllers.

4. In a die stock, the combination of a rotary frame having a sleeve portion and a front plate, radial housings integral with the front plate and sleeve and having passageways rectangular in cross section, chasers rectangular in cross section occupying said passageways, said chasers being recessed at one side, a series of wedges rectangular in cross section extending longitudinally through the housings and bearing against shoulders provided by recessing the chasers, a front ring to which the ends of the wedges are rigidly secured, and means carried by the front ring for abutting the pipe being threaded.

In testimony whereof I hereunto affix my signature. I

ALBERT H. BATES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

